1. Field of the Invention
The present invention relates to an amplifying circuit and a current-voltage conversion circuit.
2. Description of the Related Art
In general current feedback amplifiers, a PNP transistor and an NPN transistor are provided to an input stage, and an input signal is supplied to a base of the PNP transistor and a base of the NPN transistor. A collector of the PNP transistor is connected to a negative power source, and a collector of the NPN transistor is connected to a positive power source. An emitter of the PNP transistor is connected to the positive power source via a first bias circuit (first constant current circuit), and an emitter of the NPN transistor is connected to the negative power source via a second bias circuit (second constant current circuit). Thus, in general current feedback amplifiers, since a plurality of bias circuits composed of constant current circuits should be provided, a number of parts increases, and a circuit configuration becomes complicated.